UVA11532 Simple Adjacency Maximization位运算

Posted 2021-06-28 海岛Blog

Find the smallest integer N that has both of the following properties:

1. The binary representation of N has exactly P 1’s & exactly Q 0’s. (Leading Zeroes are allowed).
2. The number of 1’s adjacent to one or more 0 in the binary representation is maximized.

Input
The first line of the input file contains a single integer C, the number of test cases in the input file. Each of the next C lines contains two non-negative integers P & Q (1 ≤ P + Q ≤ 50).
Output
For each test case a print the value of N, as explained in the statement, in a line by itself.
Sample Input
3
4 3
1 1
3 2
Sample Output
45
1
13

问题链接：UVA11532 Simple Adjacency Maximization
问题简述：（略）
问题分析：简单题，用位运算来解决，不解释。
程序说明：（略）
参考链接：（略）
题记：（略）

AC的C++语言程序如下：

/* UVA11532 Simple Adjacency Maximization */

#include <bits/stdc++.h>

using namespace std;

int main()
{
    int t, p, q;
    scanf("%d", &t);
    while (t--) {
        scanf("%d%d", &p, &q);

        long long ans = 0, digit = 0;
        while (p >= 2 && q >= 1) {
            ans |= (1LL << digit) | (1LL << (digit + 2));
            digit += 3;
            p -= 2, q -= 1;
        }
        if (p == 1 && q >= 1)
            ans |= 1LL << digit, digit += 2, p--, q--;
        while (p) ans = (ans << 1) | 1, digit++, p--;

        printf("%lld\\n", ans);
    }

    return 0;
}